Growth of the remnant embryonic kidney (the mesonephros), as expressed by wet weight, was more rapid in the chick embryos with experimentally induced unilateral renal agenes is compared to controls. The difference was significant between embryonic days 8-12, when the doubled weights of remnant kidneys were increased compared with the weights of paired control kidneys. The excessive growth of the mesonephros ceased on day 14, when the normal physiological regression of the embryonic kidney begins. In the definitive kidney, the metanephros, no significant differences in weights of the control vs. remnant metanephros were found on days 10-14. The characteristics of increased mesonephric growth were evaluated by determination of DNA/protein ratios in homogenates of the kidneys. Significant cellular hypertrophy was found in both the mesonephros and metanephros of the embryos with URA on day 10. Additionally, a non-significant cellular hyperplasia was also revealed in the remnant mesonephros on day 8. This gives evidence that the growth stimuli to the mesonephroi were probably strongest between days 8-10 and that they manifested in the remnant mesonephros only. and Obsahuje bibliografii a bibliografické odkazy
Nucleotidase activity and Ca-uptake were characterized in endoplasmic reticulum (ER) enriched rat submandibular gland (SMG) microsomal preparations. (i ) Ca-uptake had characteristics of an ER Ca-ATPase. (ii) Nucleotidase activity was equally stimulated by calcium, magnesium and manganese, but with different Km values. (iii) Specific inhibitors of P-type Ca-ATPases were ineffective on nucleotidase activity, demonstrating that this activity was not related to calcium uptake and did not correspond to classical Ca2+ pumps. (iv) ATP and UTP were more efficient substrates, whereas ADP and UDP were hydrolyzed at significantly slower rate. (v) Nucleotidase activity was sensitive to mild detergent solubilization and insensitive to ionophore addition. (vi) Nucleotidase activity was strongly inhibited by suramin, a nucleoside triphosphate diphosphohydrolase (NTPDase) inhibitor. (vii) Nucleotidase activity exponentially diminished as function of time. All these observations are consistent with a NTPDase identity. The presence of a NTPDase was demonstrated by immunohistochemistry in rat SMG. Immunoreactivity was stronger in ductal cells than in mucous and serous acini. Although this enzyme was observed in the plasma membrane, colocalization with the ER marker calnexin revealed a specific subcellular localization in this organelle of all three types of cell. The putative function of this NTPDase activity in salivary glands is discussed., M. A. Ostuni ...[et al.]., and Obsahuje seznam literatury
During shock, prognosis of a patient depends largely on intestinal barrier function. The potency of gut epithelium to represent an obstacle to toxins is determined by the blood supply. All established methods of mucosal function determination necessitate the functional involvement of bloodstream. Microdialysis allows monitoring of extracellular substances in the gut submucosa, but its potential use for gut barrier integrity assessment is unknown. Twelve rats underwent perfusion of the descending colon either with 20 % ethanol or control medium (vehicle). Both media contained equal amounts of a radioactive tracer substance (51Cr-EDTA). Mucosal permeability for 51Cr-EDTA was assessed by microdialysate to luminal perfusate activity ratios. Sampling was performed using the colon submucosal microdialysis technique. The group subjected to ethanol treatment had profound macro- and microscopical alterations in perfused colonic segment associated with a significant increase in tracer permeability during ethanol exposure (2.354±0.298 % for ethanol as opposed to 0.209±0.102 % for control group, p<0.01), which remained elevated for 60 min after cessation of ethanol administration (3.352±0.188 % for ethanol compared to 0.140± 0.0838 % for the control group, p<0.001). Submucosal microdialysis with radioactive tracer substance can be considered a feasible and advantageous alternative of gut barrier function estimation. Parallel monitoring of local tissue chemistry with this method remains a challenge in the future., N. Cibiček, H. Živná, Z. Zadák, J. Kulíř, E. Čermáková, V. Palička., and Obsahuje bibliografii a bibliografické odkazy
This investigation addresses the interaction of insulin (INS) and glucocorticoid (GC) signaling in the hepatic regulation of tryptophan oxygenase (TO) enzyme activity in the rat. Male Wistar rats (200-250 g b.w) received an injection of the different doses of INS (10, 25, 50, 70 and 100 μg/200 g b.w., i.p.) and were used for experiments 3 h and 18 h after INS administration. This study shows that maximum of TO activity was found at dose of 50 μg of INS with peak increases observed at 3 h and 18 h after injection of INS, while INS had no effect on TO activity in adrenalectomized rats. The analysis of INS effects on glucocorticoid receptor-complex (GC/GR complex) stability shows that complexes from INS-treated rats are less stable than those from control animals. In addition, INS-stimulated stability of glucocorticoid receptor (GR) protein was significantly increased from the controls. Furthermore, the results show that GC/GR complexes from INS-treated rats could be activated and accumulated at higher rate in cell nuclei of control animals. These data support the involvement of INS in modulation of GC signaling pathway which mediates, in part, the activity of TO., E. R. Isenović, Z. Zakula, G. Koricanac, N. Ribarac-Stepić., and Obsahuje bibliografii a bibliografické odkazy
The endothelium of different organs displays a remarkable heterogeneity, although it presents many common functional and morphological features. However, despite our knowledge of heterogeneity among endothelial cells from different sites, the differences between brain microvascular endothelial cells (BMEC) and coronary microvascular endothelial cells (CMEC) are poorly defined. The aim of this study was to investigate whether BMEC are distinct from CMEC at the protein level. Using the proteomic approach, we comparatively analyzed the proteome of cultured BMEC and CMEC. We reproducibly separated over 2000 polypeptides by using two-dimensional electrophoresis (2-DE) at pH range of 3-10. Using PDQuest software to process the 2-DE gel images, forty-seven protein spots were differentially expressed in the two-endothelial cells. Of these, thirty-five proteins are highly expressed in BMEC, whereas twelve proteins are highly expressed in CMEC. Fifteen proteins in BMEC and seven proteins in CMEC were identified with high confidence by matrix-associated laser desorption ionization time-of-flight mass spectrometer (MALDI-TOF-MS). Our data suggested that BMEC and CMEC were different in several aspects including cytokine and growth-related molecules, stress-related proteins, metabolic enzymes, signal transduction proteins and others. The identification of a set of proteins preferentially expressed in BMEC and CMEC provided new data on the heterogeneity of the endothelium., L. Lu, P.-Y. Yang, Y.-Ch. Rui, H. Kang, J. Zhang, J.-P. Zhang, W.-H. Feng., and Obsahuje bibliografii a bibliografické odkazy
In this study, susceptibility of inbred C57BL/6 and outbred NMRI mice to monosodium glutamate (MSG) obesity or diet-induced obesity (DIO) was compared in terms of food intake, body weight, adiposity as well as leptin, insulin and glucose levels. MSG obesity is an early-onset obesity resulting from MSG-induced lesions in arcuate nucleus to neonatal mice. Both male and female C57BL/6 and NMRI mice with MSG obesity did not differ in body weight from their lean controls, but had dramatically increased fat to body weight ratio. All MSG obese mice developed severe hyperleptinemia, more remarkable in females, but only NMRI male mice showed massive hyperinsulinemia and an extremely high HOMA index that pointed to development of insulin resistance. Diet-induced obesity is a late-onset obesity; it developed during 16-week-long feeding with high-fat diet containing 60 % calories as fat. Inbred C57BL/6 mice, which are frequently used in DIO studies, both male and female, had significantly increased fat to body weight ratio and leptin and glucose levels compared with their appropriate lean controls, but only female C57BL/6 mice had also significantly elevated body weight and insulin level. NMRI mice were less prone to DIO than C57BL/6 ones and did not show significant changes in metabolic parameters after feeding with high-fat diet., R. Matyšková, L. Maletínská, J. Maixnerová, Z. Pirník, A. Kiss, B. Železná., and Obsahuje bibliografii a bibliografické odkazy
Cytokiny jsou proteiny, které regulují růst, diferenciaci a aktivaci buněk. Jejich účinek se široce využívá pro léčbu zánětlivých a nádorových onemocnění. Anti-cytokinová léčba je velmi slibná, ale přinese v blízké budoucnosti velké finanční zatížení zdravotnictví., Cytokines are proteins that regulate the growth, differentiation and activation of cells. Their functions are used in therapy of inflammatory diseases and cancer. Antibody blockade of cytokines seems to be very promising, but it will result in considerable financial burden for healthcare in future., and Ilja Trebichavský.
This study sought to evaluate whether consumption of polyphenol extract from Cognac (CPC) modulates platelet activation and cardiovascular reactivity in rats. Male Wistar rats were treated daily for 4 weeks by intra-gastric gavage receiving CPC at 80 mg/kg/day or vehicle (5 % glucose). Platelet adhesion and aggregation in response to different activators were assessed. Cardiac and vascular reactivity in response to various agonists as well as NO measurement by electron paramagnetic resonance technique were investigated in isolated heart and thoracic aorta. Oral administration of CPC decreased platelet aggregation induced by ADP but not by collagen. CPC did not affect adhesion to collagen. The chronotropic but not the inotropic response to isoprenaline was reduced without alteration of NO production in hearts from CPC-treated rats. CPC treatment did not affect ex vivo relaxation to acetylcholine nor NO content of rat aorta. CPC did not significantly alter the response to phenylephrine in aorta despite the participation of endothelial vasoconstrictor products. In summary, chronic treatment with CPC has no impact on ex vivo vascular and cardiac reactivity; however, it reduced heart work and platelet aggregation. These data suggest the existence of compounds in Cognac that may decrease the risk of coronary thrombosis and protect against some cardiac diseases., J. Švíglerová, J. Kuncová, L. Nalos, J. Slavíková, M. Štengl., and Obsahuje bibliografii a bibliografické odkazy
We have found that the determination of thiodiglycolic acid (TDGA) in urine may help to characterize metabolic imbalance of substances participating in methionine synthesis, which leads to hyperhomocystinuria. From the metabolic scheme, based on a proper combination of known facts, we attempted to theoretically explain and to demonstrate the possibilities of TDGA formation via different ways of homocysteine transformation. This scheme was used in evaluating the results obtained by testing urine of a woman suffering from impaired function of methionine synthase reductase (CblE type of homocystinuria). The amount of TDGA excreted in her morning urine was very sensitive to the changes in her treatment based upon a combination of N5-formyl tetrahydrofolate, betaine and vitamin B12. Vitamin B12 given in the evening either alone or together with betaine increased the TDGA excretion in the morning urine up to ten times. On the other hand, in the absence of vitamin B12, betaine in combination with N5-formyl tetrahydrofolate hindered the appearance of TDGA in the morning urine. Generally, the determination of TDGA in urine of an appropriately pretreated patient may indicate the degree of success of the treatment., T. Navrátil, M. Petr, Z. Šenholdová, K. Přistoupilová, T. I. Přistoupil, M. Heyrovský, D. Pelclová, E. Kohlíková., and Obsahuje bibliografii a bibliografické odkazy
Under normal conditions, antioxidants at the corneal surface are balanced with the production of reactive oxygen species without any toxic effects. Danger from oxidative stress appears when natural antioxidants are overwhelmed leading to antioxidant/prooxidant imbalance. The aim of the present study was to examine the activities of enzymes contributing to the antioxidant/prooxidant balance in normal corneal epithelium of various mammals. The enzyme activities of antioxidant superoxide dismutase and glutathione peroxidase, as well as prooxidant xanthine oxidoreductase/xanthine oxidase were examined using biochemical methods. Results show that superoxide dismutase activity is high in rabbits and guinea pigs, whereas in pigs the activity is low and in cows it is nearly absent. In contrast, glutathione peroxidase activity is high in cows, pigs and rabbits, whereas in guinea pigs the activity is low. As far as prooxidant enzymes are concerned, elevated xanthine oxidoreductase/xanthine oxidase activities were found in rabbits, lower activities in guinea pigs, very low activity in cows and no activity in pigs. In conclusion, the above results demonstrate inter-species variations in activities of enzymes participating in antioxidant/prooxidant balance in the corneal epithelium. It is suggested that the levels of antioxidant and prooxidant enzymes studied in the corneal epithelium might be associated with the diurnal or nocturnal activity of animals. UV rays decompose hydrogen peroxide to damaging hydroxyl radicals and perhaps for this reason large animals with diurnal activity (cow, pig) require more effective peroxide removal (high glutathione peroxidase activity) together with the suppression of peroxide production (low superoxide dismutase activity, low xanthine oxidoreductase activity)., J. Kovačeva, J. Pláteník, M. Vejražka, S. Štípek, T. Ardan, Č. Čejka, A. Midelfart, J. Čejková., and Obsahuje bibliografii a bibliografické odkazy